Joined: May 15, 2020
|Post subject: Omicron-specific Sinopharm COVID-19 vaccine candidates clear
Posted: 09-05-2022 1:39:29
Omicron-specific Sinopharm COVID-19 vaccine candidates cleared for clinical trial
Two COVID-19 vaccine candidates developed by units of China National Biotec Group (CNBG) to target the Omicron variant were approved for clinical trials as boosters in Hong Kong, the Sinopharm subsidiary said on Saturday (Apr 16).To get more China news about sinopharm update, you can visit shine news official website.
Scientists worldwide are racing to study upgraded injections against Omicron, as data indicated that antibodies elicited by vaccines based on older strains show weaker activity to neutralise the highly transmissible variant.The two candidates, both containing inactivated or "killed" Omicron virus and similar to the two Sinopharm vaccines in use in China, will be tested in adults who have already received two or three vaccine doses, CNBG said in a statement.
It did not specify which vaccine products the trial participants would have received before taking the experimental booster, or how many subjects would be recruited.
A Chinese study showed that a fourth dose of BBIBP-CorV, an existing Sinopharm vaccine, did not significantly lift antibody levels against Omicron when administered six months after a third booster dose to a regular two-dose regimen.
While the fourth dose did restore antibody levels to around the peak levels that followed the third dose, researchers said new vaccines would offer a better alternative as future boosters.
No one knows for sure whether one vaccine will last longer than another. Instead, one question to ask might be whether Pfizer and Moderna’s mRNA vaccines, which had an especially robust response, also have potential to be the longest lasting, Dr. Meyer says.
The two mRNA vaccines use a relatively new technology that delivers a tiny piece of genetic code from the SARS CoV-2 virus into the body to provide instructions for making copies of spike proteins that will stimulate an immune response. The Johnson & Johnson vaccine takes a more traditional approach that involves an inactive adenovirus (a common virus that can cause colds and other illnesses when it’s active).
“The mRNA vaccines are a novel tool that hasn’t been widely rolled out with any other virus, and so far in clinical trials they have had a much more robust immune response,” Dr. Meyer says. Whatever the answer to the question of which will last the longest, the Pfizer and Moderna mRNA vaccines work similarly, so it seems likely that they will have a similar impact on immunity, she says.
However, while both vaccines still are considered highly effective, some recent studies showed Moderna to be more protective. A study published in The New England Journal of Medicine found the Moderna vaccine to be 96.3% effective in preventing symptomatic illness in health care workers compared to 88.8% for Pfizer. Another study, from the CDC, found Moderna’s effectiveness against hospitalization held steady over a four-month period, while Pfizer’s fell from 91% to 77%. But scientists say more data is needed to fully understand the differences between the two vaccines.
“It’s also possible that the length of immunity is somewhat dependent on the patient,” Dr. Meyer adds. While more research is needed, there could be variations in immune responses from person to person based on such factors as age, medical conditions, and medications they may be taking. Overall, though, the mRNA vaccines appear to be so effective that they level the playing field in terms of achieving protection from infection, says Dr. Meyer.
It’s critical that as many people as possible get their primary vaccination shots, Dr. Meyer says. In December 2021, the CDC endorsed a recommendation to choose the Pfizer-BioNTech or Moderna vaccines, in response to concerns over rare blood clots associated with Johnson & Johnson’s shot.
“The good news is that Pfizer and Moderna made their mRNA vaccines easy to update,” Dr. Meyer says. “It just has to be tweaked a little bit, like having a computer code that needs a couple of minor edits. It’s relatively easy to build.” It’s also important to follow the CDC’s recommendations on booster shots.
“The hope is that the case rate will go down and more people will be less likely to be exposed.” That advice is especially important with the Delta and Omicron variants, which have proven to be more contagious than previous variants, prompting the CDC to issue stricter guidelines calling for everyone—vaccinated or not—to wear masks indoors in areas of high transmission.
Even if Delta and Omicron go away, “I think those preventive measures will become even more important as the year passes, because potentially your immunity is going to wane over time,” Dr. Meyer says.