Although there is no evidence that people immunized with one of the vaccines have less protection against the variants, both companies said they have started looking at ways to account for developmental mutations.
The B.1.351 variant first seen in South Africa is of particular concern. It contains a mutation that helps to evade the body’s immune response to infection. The B.1.1.7 variant first seen in the UK is also a cause for concern as the mutations appear to be more transmissible so that they spread better and can cause serious illness.
Researchers are also finding variants across the US that have developed mutations that help them evade the immune system.
Pfizer and its partner BioNTech said Thursday they have begun testing how well the addition of a third dose of their authorized vaccine can protect against new variants.
The study will look at the safety and immune response of a booster dose in up to 144 participants from the earlier Phase 1 trial in the US, including a subset of older adults up to 85 years. It will also involve testing how well their antibodies are the companies will be able to neutralize “interests” in the laboratory.
Volunteers receive a third dose between 6 and 12 months after their previous two doses. The dose will be the same as currently approved: 30 micrograms.
“This promotion study is critical to understanding the safety of a third dose and efficacy against circulating strains,” said Pfizer CEO Dr. Albert Bourla, said in a statement.
Separately, Pfizer and BioNTech are also ‘in ongoing discussions with regulators’ about the possible testing of a vaccine that has been modified to protect against variants in a phase 1/2 study.
However, Bourla noted that the companies have not yet seen compelling evidence that variants are resistant to the vaccine, although they are taking steps to be prepared.
Moderna said late Wednesday that it had produced an updated version of its Covid-19 vaccine to combat the B.1.351 variant first seen in South Africa. Initial doses were sent to the National Institutes of Health for a clinical study.
The new vaccine, called mRNA-1273.351, will be evaluated as a stimulator for people who have already been vaccinated against coronavirus and as a primary vaccine for people who have not yet had coronavirus and have not yet had to be vaccinated.
Moderna said it will also evaluate a “multivalent” booster shot that combines the new vaccine formulation with the current vaccine.
In addition, the company said it had begun testing whether a third, lower dose of the current Covid-19 vaccine could increase immunity to coronavirus variants, and some study participants were already receiving third doses.
“We are rapidly testing updates of the vaccines that address emerging variants of the virus in the clinic. Moderna is committed to making as many updates to our vaccine as possible until the pandemic is under control. We hope to show that booster doses, if necessary, can be done at lower dose levels, which will enable us to provide many more doses to the world community in late 2021 and 2022, ‘said Stephane Bancel, CEO of Moderna, in’ a statement said.
Moderna did not say how long he expects the studies to take, or when the new vaccine will be available, if approved. The current vaccine mentions two doses of 100 micrograms that are about a month apart. The new booster doses are evaluated at half level and lower.
The U.S. Food and Drug Administration on Monday announced new guidelines that will streamline and accelerate the process of updating vaccines to target variants. According to an official, it could involve several hundred individuals and take several months.
“It’s going to be in the order of a few hundred individuals in terms of size, and we would expect it to take a few months,” said Dr. Peter Marks, director of the FDA’s center for evaluation and research on biology, during a link Monday with reporters.
Both the Moderna and Pfizer vaccines use a new technology using messenger RNA or mRNA that simply requires a genetic code. The design is intended to easily update the vaccines, without the preparation months required to change a flu vaccine, for example.