Modified vaccines can be tested in small-scale trials
REPUBLIKA.CO.ID, NEWYORK – There is an assumption that if the new coronavirus mutates until the current Covid-19 vaccine is no longer effective in fighting the virus, researchers must modify the vaccine. However, there are arguments regarding this assumption.
New United States Food and Drug Administration (FDA) guidelines suggest lengthy and extensive clinical trials may not be required to test modified vaccines.
In contrast, modified vaccines can be tested in small-scale trials such as those done to develop a flu vaccine every year.
“We know the country is eager to return to a new normal, and the emergence of a virus variant raises new concerns about the performance of this (vaccine) product,” said Janet Woodcock, acting FDA commissioner, in a statement. Livescience, on Tuesday (23/2).
“By issuing this guide, we want the American public to know that we are using everything we can to fight this pandemic, including turning around as the virus adapts,” continued Woodcock.
Woodcock said the current evidence shows Pfizer and Moderna are still effective against the circulating Covid-19 variant. The two vaccines are the only two vaccines allowed for emergency use in the US.
“Studies show, however, they may be less effective against the variant first detected in South Africa, known as variant B.1.351, than other variants. But if the virus evolves to become sufficiently or completely resistant to the current Covid-19 vaccine, then it may be necessary to modify it, “said Woodcock.
Woodcock says the mRNA technology used to make both vaccines allows for rapid modification. The company that makes the two vaccines said it could make a modified version within six weeks.
“Because companies will modify the same vaccine only slightly to make it better than the new variant, extensive clinical trials involving testing the vaccine against placebo in thousands of people may not be necessary,” said Woodcock.
On the contrary, new guidelines FDA suggest testing the modified vaccine in a small group of volunteers may be sufficient. After being vaccinated, these volunteers will provide blood samples to be tested in the laboratory.