Johnson & Johnson COVID-19 vaccine produces strong immune response in early trial

By Vishwadha Chander

A single dose of Johnson & Johnson's experimental COVID-19 vaccine produced a strong immune response against the coronavirus in an early-to-mid stage clinical trial, according to interim results.

The vaccine, called Ad26.COV2.S, was equally well-tolerated at two different doses, the results showed. A single shot, versus a rival two-dose approach being tested by Moderna Inc and Pfizer Inc, could simplify distribution of the vaccine.

However, it is unclear whether elderly people, one of the populations most at risk from the virus, will be protected to the same degree as younger people with the J&J vaccine.

The trial in close to 1,000 healthy adults, which is backed by the U.S. government, began after the J&J vaccine was found in July to offer strong protection in a single dose to monkeys.

Based on the current results, J&J on Sept 23 kicked off a final 60,000-person trial, which could pave the way for an application for regulatory approval. The company said it expects results of that so-called Phase 3 trial by the end of the year or early next year.

The results, released on the medical website medRxiv, have not been peer-reviewed. (

Researchers, including those from J&J's unit Janssen Pharmaceuticals, said 98% of participants with data available for the interim analysis had neutralizing antibodies, which defend cells from pathogens, 29 days after vaccination.

However, immune response results were available from only a small number of people - 15 participants - over 65 years old, limiting the interpretation.

In participants older than 65, the rate of adverse reactions such as fatigue and muscle aches was 36%, much lower than the 64% seen in younger participants, the results showed, suggesting the immune response in older people may not be as strong.

The researchers said more details on safety and effectiveness will follow when the study is completed.

For now, the results justify why more studies are needed in larger numbers to look for serious adverse effects, Dr Barry Bloom, a professor at Harvard T.H. Chan School of Public Health who was not involved in the J&J trial, told Reuters.

"Overall, the vaccine is doing what you would expect it to do if you were to move it to Phase 3 trials," Bloom said.

© Thomson Reuters 2020.

©2020 GPlusMedia Inc.

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Fingers crossed.

3 ( +3 / -0 )

It is a nice touch to directly put the link to the manuscript on the article. The tests are obviously not complete and require more participants being followed for longer time, but the activation of both humoral and cellular immunity seems to be extremely good.

From the manuscript, a dose equivalent to 1e10 (10 trillion) viruses seems high but it is actually a really low amount, equivalent to less than one microgram of protein, it is surprising that such strong effects can be observed with such a little amount and that is a very positive finding because it means production can be faster and cheaper, and possible negative side effects minimized much more easily.

1 ( +2 / -1 )

Sorry, 50-100 trillion virions, still a very low dose under a microgram.

2 ( +3 / -1 )


Thanks for your information but I guess that 99% of the posters here are no medical experts, including me, and we don't understand your information.

I guess you are a scientist or medical expert.

So please just tell us: will the vaccine be effective and when can the public get it?

0 ( +2 / -2 )

So please just tell us: will the vaccine be effective and when can the public get it?

Unfortunately that is something that requires time and completing the full clinical trials to be known.

At this time what we know is that the vaccine, even in tiny doses, produce very strong immunity in the two principal ways we have to measure, immunity that depends on antibodies (that may be short term) and immunity that depends on cells (that apparently works for much longer against highly pathogenic coronaviruses). We also know that up until now there is not dangerous side effects in the people that have been vaccinated.

What we still need to know and that requires more tests is to see if the immunity measured actually means the people is protected against infection and that the vaccinated people have no negative reactions when they get the real infection. It is very unusual but for some diseases having good cellular and antibody immunity is not enough and people can get sick or even have dangerous reactions after the infection.

For this kind of vaccine what is left to do is the phase III clinical trials that take at least 6 months to be completed. So it would be ready for April 2021 at the soonest, as long as everything keeps going well.

1 ( +2 / -1 )

Great news !!.. Sorry antivaxxer lsrs..

0 ( +1 / -1 )

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