Pfizer aims to implement boosters and a new vaccine based on SARS-CoV-2 Delta variant

By Angela Betsaida B. Laguipo, BSNJul 11 2021

Coronavirus disease (COVID-19) pandemic waves are taking a toll on many countries due to emerging variants. Globally, a surge of cases has been reported of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant of concern (VOC) B.1.617.2 Delta.

The rise in infections alone is troubling and can be linked to more deaths due to an overburdened healthcare system, however, the Delta variant has been shown to be much more harmful than the Alpha variant, causing twice as many hospitalizations.

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Pfizer booster dose

The drugmaker Pfizer, one of the companies behind the Pfizer-BioNTech vaccine, or BNT162b2, awaits the green light to develop a COVID-19 booster shot that can protect against emerging variants. Pfizer’s COVID-19 vaccine has been shown to be 95% effective in an ongoing large-scale clinical trial against the original SARS-CoV-2 strain.

Pfizer and BioNTech said they see waning immunity from its COVID-19 vaccine, and it plans to develop a booster dose that will add protection. The companies plan to seek emergency use authorization from the U.S. Food and Drug Administration (FDA) for a booster dose in August after it released evidence of how well a third dose would work.

The companies also said that there is encouraging data from administering a third dose for a booster shot of the current BNT162b2 vaccine, currently being given in two doses. The initial data from the study showed that a booster dose given six months after the second dose has a consistent tolerability profile while inducing neutralization titers against the wild type and the Beta variant, which are 5 to 10 times higher than after two primary doses.

In addition, a study showed that immune sera collected after the second dose of BNT162b2 have strong neutralization titers against the Delta variant in laboratory tests. Therefore, Pfizer estimates that a third dose can boost the titers more. Currently, they are conducting preclinical and clinical trials to validate the hypothesis.

“The companies expect to publish more definitive data soon as well as in a peer-reviewed journal and plan to submit the data to the FDA, EMA, and other regulatory authorities in the coming weeks,” the two companies said in a statement.

However, in a joint statement by the FDA and the U.S. Centers for Disease Control and Prevention (CDC), fully vaccinated individuals do not need a booster shot at this time. In addition, the two agencies emphasized that the COVID-19 vaccines in the country are effective, and virtually all hospitalizations and deaths are among those who remain unvaccinated.

“We are prepared for booster doses if and when the science demonstrates they are needed,” the statement said.

High transmission in low vaccination areas

In a press briefing by The White House, the country’s top health officials said there would be an increase in COVID-19 cases amid the spread of new variants. However, the country now has over 80 percent of seniors 65 and over and those with comorbidities vaccinated against COVID-19. These groups are most at risk of developing severe COVID-19.

The report added that though new variants emerge, vaccinated people 12 and over are less likely to get hospitalized due to the infection. The main focus of the government is to reach those who are hesitant to receive a COVID-19 vaccine. In the summer, the government plans to vaccinate millions of people by going from one community to another. When more people receive the vaccine, they are protected from COVID-19, including the Delta variant.