Medical experts told CNBC that there wasn’t enough research on how much protection could be achieved with the fourth dose.
Justin Sullivan | Getty Images
The Food and Drug Administration on Thursday said vaccine manufacturers need to update their Covid-19 booster shots to target the latest Omicron subvariants that are becoming established in the United States.
Dr. Peter Markes, head of the FDA’s vaccine division, said manufacturers will target Omicron BA.4 and BA.5 in addition to the original strain of the virus that first appeared in Wuhan, China in 2019. Said that the shot needs to be updated.
The FDA wants to update its booster shots to provide longer lasting protection ahead of the fall. Public health experts predict that as immunity from the vaccine weakens and people head indoors, the wave of infection will continue again to escape the cold.
According to Marks, the double-dose primary vaccination series will not change immediately. In other words, fully vaccinated people do not start from scratch in the fall. They will simply receive Omicron shots to enhance their defense against the virus. People who have not yet been vaccinated may first be vaccinated twice with the original vaccine and then with the new version of the jab.
According to Marks, the FDA will review the safety, efficacy, and manufacturing quality of the new vaccine to ensure it meets the highest standards before permitting public use.
A panel of independent FDA experts voted overwhelmingly on Tuesday and recommended a new prescription after an all-day meeting assessing the advantages and disadvantages of updating shots prior to the fall booster campaign in the United States.
However, vaccine makers are struggling to keep up with the rapid evolution of the virus. Pfizer and Moderna have developed an Omicron Shot targeting the original version of BA.1. This caused a large wave of infection that struck the hospital with sick patients during the winter.
However, BA.1 has been extruded by other Omicron submutants and is no longer prevalent in the United States. According to the Centers for Disease Control and Prevention, Omicron BA.4 and BA.5 currently account for more than 50% of Covid infections in the United States. Prevention.
It’s unclear how long it will take for vaccine makers to switch gears and develop shots containing BA.4 and BA.5 instead of the original version of Omicron. According to Marks, the FDA has asked companies to begin clinical trials of these new subvariants. The FDA’s expert committee has generally endorsed targeting BA.4 and BA.5 to keep up with the evolution of the virus.
Pfizer and Moderna released clinical trial data on Tuesday showing that the updated shots elicited a stronger immune response to Omicron BA.1 than the original version of the vaccine approved by the FDA in December 2020. I did. According to updated shots and data based on BA.1, the immune response was still strong, but did not work as well for BA.4 and BA.5.
The survey is small, with only a few hundred participants, and currently there is no data on how well shots work in the real world. The immune response is generally regarded as a good indicator of how well a vaccine is protected from disease.
Some FDA panel members have stated that they need more data on their effectiveness before deploying new shots. Other panel members said it is unclear how adding new ingredients to the vaccine could affect a form of heart inflammation called myocarditis. Pfizer and Moderna shots are associated with an increased risk of myocarditis after the second dose in adolescent boys. However, according to the CDC, Covid infections have a higher risk of myocarditis than vaccination.
The United States lacks both time and money to prepare a new vaccine for the fall. Manufacturers only have three months to make a shot, but even if they meet the timeline, the United States may not be able to buy a vaccine for everyone.
Congress hasn’t passed funding to the United States to buy vaccines in the fall, and the Biden administration has only enough money to buy shots for people at high risk of illness, such as the elderly. I warned that it might not be. The White House has shifted $ 5 billion from other parts of the pandemic response to begin negotiations with vaccine makers.
All currently licensed Covid vaccines are based solely on the original version of the virus that appeared in China over two years ago. Shot does not provide the same level of protection against infections and mild illnesses because the virus is so mutated. There are concerns that this protection may weaken as the virus continues to evolve, but they are still generally better at preventing serious illnesses.
The virus contains a protein called spikes that is used to invade human cells. The current shot uses a copy of the spike from the original version of the virus to trigger an immune response that protects against disease. The immune response recognizes a spike in the virus and sends an antibody that blocks it from invading human cells.
However, antibodies triggered by the original vaccine have difficulty recognizing highly mutated versions of spikes in the Omicron subvariant. In other words, Omicron has slipped through the barriers built by the vaccine, causing infections and mild illnesses even in people who continue to inject.