Health experts told CNBC there’s still not enough research on how protective a fourth dose might be.
Justin Sullivan | beautiful pictures
The Food and Drug Administration on Thursday said vaccine makers should update their Covid-19 booster shots to target the most recent omicron subvariables gaining ground. in U.S.A.
Dr. Peter Marks, the FDA’s head of vaccines, said manufacturers should update their injections to target omicrons BA.4 and BA.5 in addition to the strain of the virus that originally emerged. in Wuhan, China in 2019.
The FDA wants to update the booster shots to provide more lasting protection before the fall, when public health experts expect another wave of infections as immunity to the vaccine wanes and people get sick. people enter the house to hide from the weather. Vibrant spreads more easily in the home.
For now, the two-dose primary series of immunizations will remain unchanged, Marks said. In other words, people who are fully immunized will not start over in the fall. They will simply receive an omicron injection to increase their protection against the virus. And those who have not been vaccinated will get two doses of the original vaccine first, and then a dose of the new vaccine.
The FDA’s panel of independent experts voted overwhelmingly on Tuesday to recommend a vaccine switch after an all-day meeting in which they assessed the benefits and downsides of updating the shots.
Vaccine manufacturers are having a hard time keeping up with the rapid evolution of the virus. Pfizer and Moderna developed their omicron footage to target the original version of the variant, BA.1., which caused a large wave of infections during the winter.
But BA.1 has been pushed out by other omicrons and is no longer circulating in the U.S. Omicron BA.4 and BA.5 now account for more than 50% of Covid infections in the United States, according to the Centers for Control Diseases and Prevention.
Pfizer and Moderna presented clinical trial data on Tuesday demonstrating that their updated shots triggered an immune response against omicron BA.1 stronger than the FDA’s original version of the vaccine. approved for use in December 2020. The updated injections, based on BA.1 , did not perform well against BA.4 and BA.5 although the immune response was still strong.
The studies are small with only a few hundred participants, and there is currently no data on how well photos will perform in the real world. Immune response is often considered a good indicator of how well a vaccine will protect against disease.
It is unclear how long it will take for vaccine manufacturers to shift gears and develop injections that include BA.4 and BA.5 instead of the original version of omicron. Marks said the FDA has asked companies to begin clinical trials on these newer secondary variables. The FDA’s panel of experts generally prioritizes targeting BA.4 and BA.5 in an effort to keep up with virus developments.
All currently authorized Covid vaccines are based solely on the original version of the virus that emerged in China more than two years ago. The shots no longer provide the same level of protection against infections and minor illnesses because the virus has changed so much. Overall, they are still preventing serious illness, although there is concern that this protection will also wane.
This virus has a protein called spike that it uses to enter human cells. Current injections use copies of the spike from the original version of the virus to trigger an immune response that protects against disease. However, vaccine-activated protective antibodies are having difficulty recognizing highly mutated versions of the spike on omicron sub-variants.