New Johnson & Johnson figures show second-shot boosts antibodies and COVID-19 protection – however one dosage against the delta variety is still strong

The two questions which many people probably wondered about its vaccine were answered by Johnson &Johnson on September 22, 2021: How good is it against the delta variant? Virologist Maureen Ferran, at the Technology Institute in Rochester, maintained tabs on the Johnson and Johnson vaccines. It divides up the new information and explains the significance of everything.

How effective is a Johnson & Johnson dose?

Initial clinical trial data in January 2021, it has been shown four weeks following the first dose to be 66.3 percent effective in preventing COVID-19 infection with the single-shot vaccine of Johnson & Johnson. Another 85% effective way to prevent severe or critical diseases was shown in early studies.

However, the initial clinical studies and latter tests were carried out before the delta variant was responsible for nearly all COVID-19 cases in the United States. Early studies show that while COVID-19 vaccines remain efficient against this variant, their effectiveness is generally lower compared to the original strain protection.

On Sept. 21, 2021, Johnson and Johnson announced the results of a large, real-world Phase 3 clinical trail of its COVID-19 vaccine. This study collected data from March 1, 2020, through July 31, 2021, and found that the effectiveness of the vaccine did not diminish over the duration of the study, even after the delta variant became dominant in the U.S. The one-dose vaccine was 79% protective against COVID-19 infections and 81% protective for COVID-19-related hospitalizations. This indicates that a single Johnson & Johnson shot performs well, even in the presence of the delta and other variants.

2. Why might someone need a booster?

The amount of neutralizing antibodies in a person – antibodies that defend a cell from the coronavirus – is an accurate measure of protection within the first several months after vaccination. Studies show that individuals who received a Johnson & Johnson or an mRNA vaccine continue to produce some level of antibodies for at least six months after vaccination. However, neutralizing antibody levels generally start to wane over time and some evidence suggests that immunity provided by the Pfizer mRNA vaccine does the same.

This may sound bad, but it isn’t clear that lower antibody levels correlate with an increased risk of severe infection. The immune system’s long-term surveillance is done by “memory” immune cells that will prevent or reduce disease severity if a person is exposed to the coronavirus at a later time.

Therefore scientists have been collecting real-world data from vaccinated people to determine when they may become vulnerable to infection again with and without a booster shot.

3. How effective is a Johnson & Johnson booster shot?

In addition to the results of the single–shot study, on Sept 21, 2021, Johnson & Johnson also released data about booster shots. The trial gave people a second dose of the Johnson & Johnson vaccine either two or six months after the first dose. In both cases, it increased people’s defense against COVID–19.

When given two months after the first dose, protection against moderate to severe disease increased from 85% to 94% and the amount of neutralizing antibodies increased four-fold. If the booster was administered six months after the first shot, antibody levels increased 12-fold, when measured four weeks after the booster was given.

These findings suggest that although a single dose of the Johnson & Johnson vaccine provides strong, durable protection, people may still benefit from a booster because it improves the vaccine’s efficacy.

One important question is whether someone who received the Johnson & Johnson shot should get a second Johnson & Johnson dose or mix and match – get a second dose of a different vaccine. As of late September, the FDA seems more likely to approve a second dose of the Johnson & Johnson vaccine because there isn’t much data yet about a mix-and-match strategy.

4. What about the side effects?

The vast majority of vaccines – including the Johnson & Johnson and mRNA COVID-19 vaccines – produce common side effects, such as pain at the injection site, headache, fatigue, muscle and joint pain, chills and fever.

The recent study did not monitor side effects from the booster in detail, but according to Johnson & Johnson, the safety of the vaccine remained consistent and was generally well-tolerated when administered as a booster. Overall, researchers have repeatedly found that despite some rare complications, the benefits of the Johnson & Johnson vaccine far outweigh the risks.

A recent CDC study showed that unvaccinated people are almost five times more likely to be infected by the coronavirus and 29 times more likely to be hospitalized with COVID-19 compared to fully vaccinated individuals. Therefore, all the evidence suggests that the millions of Americans who are able to get vaccinated but are choosing not to are putting themselves – and others – at serious risk.

5. When might a booster be authorized?

On Sept, 22, 2021, the FDA approved booster shots for people who received the Pfizer vaccine and are 65 years of age and older, at risk of severe COVID-19 illness or whose occupations put them at greater risk of exposure. Booster shots of the Johnson & Johnson or Moderna vaccines are not yet approved, but on Sept. 19, Dr. Anthony Fauci said that the FDA could review booster data for the Moderna and Johnson & Johnson vaccines within a few weeks.