Virus World

Clinical study on nasopharyngeal cancer with an unexpected result. Patients with nasopharyngeal cancer are often treated with drugs that activate their immune system against the tumor. Scientists feared that vaccination against COVID-19 could reduce the success of cancer treatment or cause severe  —until now.  A recent study now gives the all-clear in this regard. According to the study, the cancer drugs actually worked better after vaccination with the Chinese vaccine SinoVac than in unvaccinated patients. The results of the study, which was conducted by the Universities of Bonn and Shanxi in the People’s Republic of China, are published as a “Letter to the editor” in the journal Annals of Oncology, but are already available online. Many cancer cells are capable of subverting the body’s immune response. They do this by pushing a kind of button on the immune cells, the PD-1 receptor. In this way, they effectively shut down these endogenous defense forces. Drugs can be used to block PD-1 receptors. This enables the immune system to fight the tumor more effectively. Vaccination against COVID also stimulates the immune response, involving the PD-1 receptor.

“It was feared that the vaccine would not be compatible with anti-PD-1 therapy,” explains Dr. Jian Li of the Institute of Molecular Medicine and Experimental Immunology (IMMEI) at the University Hospital Bonn. “This risk is especially true for nasopharyngeal cancer, which, like the SARS Cov-2 virus, affects the upper respiratory tract.” Together with cooperation partners from the People’s Republic of China, the bioinformatician has now investigated whether this concern is justified. More than 1,500 patients treated in 23 hospitals from all over China participated in the analysis. Such multi-center studies are considered to be particularly informative because the participants are very diverse and, moreover, the results are not distorted by regional characteristics.

Vaccinated patients responded better to cancer therapy

A subset of 373 affected individuals had been vaccinated with the Chinese COVID-19 vaccine SinoVac. “Surprisingly, they responded significantly better to anti-PD-1 therapy than the unvaccinated patients,” explains Prof. Dr. Christian Kurts, Director of IMMEI and member of the Transdisciplinary Research Area “Life & Health” and the Cluster of Excellence ImmunoSensation. “Furthermore, they did not experience severe side effects more often.” The researchers cannot say why the treatment was more successful after vaccination. “We assume that vaccination activates certain immune cells, which then attack the tumor,” says Prof. Dr. Qi Mei of Shanxi University Hospital. “We will now investigate this hypothesis further.” Nasopharyngeal cancer is quite rare in this country. In southern China and other countries in Southeast Asia, however, the disease is widespread. One of the suspected reasons for this is the frequent use of air conditioning in the hot and humid regions. Nutritional factors also appear to play an important role. In Taiwan, nasopharyngeal cancer is now considered one of the leading causes of death among young men.

Study published in Annals of Oncology. (Oct. 6, 2022):

https://doi.org/10.1016/j.annonc.2022.10.002 

A leading Chinese Covid-19 vaccine developed by Sinovac Biotech was just 50.38% effective in late-stage trials in Brazil, significantly lower than earlier results showed, according to a statement published by the government of Sao Paulo Tuesday.  While the number exceeds the threshold required for regulatory approval, it falls far below the 78% previously announced, raising questions as to the veracity of the data and fueling skepticism over the apparent lack of transparency regarding Chinese vaccines. Analysts said the efficacy rate of Sinovac's Coronavac vaccine in Brazil -- the lowest among its global competitors -- could affect international confidence in Chinese-made vaccines and hamper Beijing's effort to repair its image from its early mishandling of the initial outbreak by providing Covid-19 vaccines to developing countries. "The Butantan Institute and the Government of Sao Paulo report that the coronavirus vaccine achieved a 50.38% overall efficacy rate in the clinical study conducted in Brazil, in addition to (an efficacy rate of) 78% for mild cases and 100% for moderate and severe cases of Covid-19. All rates are higher than the 50% level required by the WHO (World Health Organization)," the statement released Tuesday said. The razor-thin margin for regulatory approval is likely to lead to concern among scientists, given that last week the Butantan institute released partial "clinical efficacy" results celebrating 78% to 100% efficacy in preventing infections. The state body financed the phase 3 trials of the vaccine, which involved 13,000 health workers across eight Brazilian states. "Regarding the overall efficacy of the analysis, we met the requirements of the World Health Organization with 50.38%," Ricardo Palacios, medical director for clinical research at the Butantan biomedical center in Sao Paulo said Tuesday during a news conference. However, on Tuesday, high-ranking members of the Brazilian Health Ministry told CNN affiliate CNN Brasil that "the effectiveness is borderline," and that because "It is at the limit. We have to wait for ANVISA (Brazilian Health Regulatory Agency) to evaluate." A representative of Sinovac said the company is discussing the result but declined to give further comment. The final efficacy rate of the vaccine will be determined by China's drug regulator, the National Medical Production Administration, according to the representative. 

Although none of the coronavirus vaccines under development has proved its efficacy yet in clinical trials, at least 5.7 billion doses have been pre-ordered  around the world. First shipments of a COVID-19 vaccine created by Western laboratories have often been snapped up by the United States. Five vaccines — three Western and two Chinese — are in Phase 3 efficacy trials involving thousands of people. In a surprise announcement, Russian President Vladimir Putin claimed Tuesday that a vaccine dubbed Sputnik V — after the Soviet satellite — conferred “sustainable immunity” against the novel coronavirus. As research laboratories around the world race to develop a vaccine, manufacturers have received financing to help them prepare to have millions of doses ready to administer in 2021 or even before the end of the year.

Oxford University, working with the Swedish-British pharmaceutical group AstraZeneca, hopes to have results by September, while the US biotech company Moderna, partnering with the U.S. National Institutes of Health (NIH), is aiming for the end of the year, possibly November. U.S. President Donald Trump has launched “Operation Warp Speed” in a bid to develop, manufacture and distribute a COVID-19 vaccine to all Americans by January 2021. Hundreds of millions of dollars have been directed to vaccine developers, including nearly $500 million to Johnson & Johnson at the end of March. The United States has allocated funding to more companies than any other nation in the hope that one of them will come up with the vaccine to counter the highly contagious virus. So far, Washington has handed out at a total of at least $9.4 billion to seven vaccine developers and signed manufacturing contracts with five of them to provide 700 million doses. The companies involved are: Johnson & Johnson, Moderna, Oxford/AztraZeneca, Novavax, Pfizer/BioNTech, Sanofi/GSK, Merck Sharp and Dohme.  Two vaccine developers — Oxford/AztraZeneca and Sanofi/GSK — have signed or are in advanced negotiations with the European Commission to provide a combined 700 million vaccine doses. Britain, because of Brexit, is negotiating a separate pre-order of 250 million doses from four developers.  Japan is counting on 490 million doses from three suppliers, including 250 million from Novavax of the United States. Pharmaceutical giant Takeda bought the rights to a Novavax vaccine for Japan, which has funded the research. It would be produced locally.

Brazil chose a similar model, ordering 100 million doses from AstraZeneca and partnering with China’s Sinovac to produce 120 millions of CoronaVac, which is already undergoing testing with Brazilians. Clinical tests of two Chinese vaccine candidates — Sinovac and Sinopharm — are well underway but only a few international partnerships have been announced, the one with Brazil and a possible one with Indonesia. Russia said 20 nations have pre-ordered 1 billion doses of Sputnik V and that with foreign partners it would be able to produce 500 million doses a year in five countries. The Coalition for Epidemic Preparedness Innovations, launched in 2017 by Norway, India, the Bill and Melinda Gates Foundation and the Wellcome Trust, seeks to ensure that there is “equitable access” to future vaccines. It has pre-ordered 300 million doses from AstraZeneca for dozens of developing countries in a partnership with The Vaccine Alliance. Billions of doses would be produced for Asia and elsewhere by the giant Serum Institute of India (SII), the largest vaccine producer in the world. Novavax and AstraZeneca have separately signed agreements with SII to produce a billion doses each for India and low- and middle-income countries on the condition that they prove their efficacy in clinical trials.

An experimental coronavirus vaccine developed by Oxford University has protected six monkeys from “heavy quantities” of the pathogen — a promising breakthrough in the worldwide race for a cure. Researchers at the National Institute of Health Rocky Mountain Laboratory injected the six rhesus macaque monkeys with the Oxford concoction, then exposed them to “heavy quantities” of COVID-19 — exposure that had consistently sickened other monkeys in the lab, the New York Times reported Monday. But 28 days later, all the chimps were still healthy.

“The rhesus macaque is pretty much the closest thing we have to humans,” Dr. Vincent Munster, who conducted the Oxford tests, told the Times. The vaccine is now set to undergo human trials, with tests scheduled for more than 6,000 people by the end of next month. If the trial proves safe and effective, the scientists are optimistic that with emergency approval from regulators, the first few million doses could be available by September, the outlet said.

The British university has had a head start in trying to develop a coronavirus vaccine — the university’s Jenner Institute ran trials on an earlier strain of the virus last year which proved harmless to humans, according to the Times. Another research company, Chinese-based SinoVac, is also making progress, however. The company said its tests on rhesus macaques also showed promise — and the company has recently started a clinical trial with 144 patients.

BEIJING (AP) — In a rare admission of the weakness of Chinese coronavirus vaccines, the country's top disease control official says their effectiveness is low and the government is considering mixing them to get a boost.  Chinese vaccines “don’t have very high protection rates,” said the director of the China Centers for Disease Control, Gao Fu, at a conference Saturday in the southwestern city of Chengdu. Beijing has distributed hundreds of millions of doses abroad while trying to promote doubt about the effectiveness of the Pfizer-BioNTech vaccine made using the previously experimental messenger RNA, or mRNA, process. “It’s now under formal consideration whether we should use different vaccines from different technical lines for the immunization process,” Gao said.  Officials at a news conference Sunday didn’t respond directly to questions about Gao’s comment or possible changes in official plans. But another CDC official said developers are working on mRNA-based vaccines. Gao did not respond to a phone call requesting further comment. “The mRNA vaccines developed in our country have also entered the clinical trial stage,” said the official, Wang Huaqing. He gave no timeline for possible use.

Experts say mixing vaccines, or sequential immunization, might boost effectiveness. Researchers in Britain are studying a possible combination of Pfizer-BioNTech and the traditional AstraZeneca vaccine. The coronavirus pandemic, which began in central China in late 2019, marks the first time the Chinese drug industry has played a role in responding to a global health emergency. Vaccines made by Sinovac, a private company, and Sinopharm, a state-owned firm, have made up the majority of Chinese vaccines distributed to several dozen countries including Mexico, Turkey, Indonesia, Hungary, Brazil and Turkey. The effectiveness of a Sinovac vaccine at preventing symptomatic infections was found to be as low as 50.4% by researchers in Brazil, near the 50% threshold at which health experts say a vaccine is useful. By comparison, the Pfizer-BioNTech vaccine has been found to be 97% effective. Health experts say Chinese vaccines are unlikely to be sold to the United States, Western Europe and Japan due to the complexity of the approval process.

A Sinovac spokesman, Liu Peicheng, acknowledged varying levels of effectiveness have been found but said that can be due to the age of people in a study, the strain of virus and other factors. Beijing has yet to approve any foreign vaccines for use in China.

Gao gave no details of possible changes in strategy but cited mRNA as a possibility. “Everyone should consider the benefits mRNA vaccines can bring for humanity,” Gao said. “We must follow it carefully and not ignore it just because we already have several types of vaccines already.” Gao previously questioned the safety of mRNA vaccines. He was quoted by the official Xinhua News Agency as saying in December he couldn’t rule out negative side effects because they were being used for the first time on healthy people. Chinese state media and popular health and science blogs also have questioned the safety and effectiveness of the Pfizer-BioNTech vaccine. As of April 2, some 34 million people in China have received both of the two doses required for Chinese vaccines and about 65 million received one, according to Gao. The Sinovac spokesman, Liu, said studies find protection “may be better” if time between vaccinations is longer than the current 14 days but gave no indication that might be made standard practice.

By Tuvan Gumrukcu and Ali Kucukgocmen ANKARA (Reuters) -A COVID-19 vaccine developed by China's Sinovac Biotech is 91.25% effective, according to interim data from a late-stage trial in Turkey, a potentially much better result than reported from a separate trial of the vaccine in Brazil.  Researchers in Brazil, which is also running a final Phase III trial of the vaccine, said on Wednesday the shot was more than 50% effective, but withheld full results at the company's request, raising questions about transparency. Turkish researchers said on Thursday no major side-effects were seen during their trial, apart from one person who had an allergic reaction. Common adverse effects caused by the vaccine were fever, mild pain and slight fatigue, they said.  The Turkish trials began on Sept. 14 and have included more than 7,000 volunteers, the researchers said, adding the results announced on Thursday were based on data from 1,322 people. 

Sinovac is the first Chinese vaccine maker to release details from late-stage clinical trials, following positive results from rival products developed by Pfizer, Moderna and AstraZeneca last month. The Turkish researchers, speaking alongside Health Minister Fahrettin Koca, said 26 of the 29 people who were infected during the trial were given placebos, adding the trial would continue until 40 people become infected. "We are now certain that the vaccine is effective and safe (to use) on Turkish people," Koca said, adding Ankara would use the data for licensing the vaccine.  He also said that researchers initially planned to announce the results after 40 people were infected, but that the findings showed the volunteers had minimal adverse effects after the shot and that it was therefore deemed safe. "Despite it being risky, we saw a very light picture where three people's PCR (COVID test) were positive, with no fever or respiratory problems... We can easily say that despite it being risky, those three people went through it very lightly," he said.

SHIPMENTS ARRIVE MONDAY

Turkey had agreed to buy 50 million doses of Sinovac's shot and receive delivery by Dec. 11 but the shipment was delayed. Koca said three million doses would arrive on Monday, adding that Turkey would vaccinate some nine million people in the first group, starting with health workers. Sinovac has also signed supply deals for its vaccine, called CoronaVac, with countries including Indonesia, Brazil, Chile and Singapore, and is negotiating with the Philippines and Malaysia. CoronaVac has been given to tens of thousands of people under an emergency use programme China launched in July targeting specific groups of high-infection risks. CoronaVac is based on traditional vaccine technology that uses inactivated coronavirus that cannot replicate in human cells to trigger an immune response. Vaccines developed by Pfizer/BioNTech and Moderna use a new technology called synthetic messenger RNA (mRNA) to activate the immune system against the virus and require far colder storage. Pfizer's treatment is the first fully tested COVID-19 shot to be administered, with rollout already under way in Britain and the United States Koca said Turkey would sign a deal with Pfizer/BioNTech for 4.5 million doses of their vaccine to be delivered by the end of March, with an option to buy a further 30 million doses later. On Thursday, Turkey's death toll from the coronavirus rose by 254 to 19,115, according to Health Ministry data, while the total number of COVID-19 infections rose by 18,102.

Sinovac is working on one of the more closely watched candidate vaccines for the disease, but trading of its shares has been long suspended. Moderna’s work on a vaccine for coronavirus has made its founders into paper billionaires. Gilead Sciences has added $10 billion to its market value since the start of 2020. And a rising tide of Covid-19 speculation has sent one major biotech index to its all-time high.

But Sinovac, a Beijing-headquartered company with a coronavirus vaccine already in human trials, has been entirely left out. Thanks to a yearslong battle for corporate control — involving a secret coup, a poison pill, and an office raid — trading of Sinovac’s shares has been halted since early 2019..