COVID-19:Why Firms are Making Billions of vaccine Doses That May Not Be Effective

         

     

• To speed up the production of a COVID-19 vaccine, manufacturers will produce doses even before last-stage clinical trials are complete.
• This is no guarantee that the vaccine will work.
• If it proves to be safe and effective, the public can be quickly vaccinated.

Before late-stage clinical trials are completed, the United States plans to order millions of doses of a promising COVID-19 vaccine manufacturers, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases (NIAID) and a member of the White House Corona virus Task Force, stated Tuesday.

“Before the end of the year,we hopefully would have close to 100 million doses, and by the beginning of 2021, we hope to have a couple of hundred million doses,” said Fauci during a live Q&A with the Journal of the American Medical Association.

However, this is not a guarantee that the vaccine will work. But if it later proves to be safe and effective, the public can be vaccinated in no time.

Pharmaceutical company AstraZeneca announced that it plans to get a similar strategy.

The company plans to distribute 2 billion doses of a COVID-19 vaccine worldwide starting in September or October, adding that this timeline depends on clinical trials taking scheduled for August.

Late-stage vaccine trials to start soon

While the US government and vaccine makers will be taking a risk by producing a vaccine early, their decision will be based on certain data, even if it is not the full phase III clinical trial data.

Dr. Davey Smith, head of the division of infectious diseases and global public health at UC San Diego School of Medicine, indicates that statisticians routinely review data throughout a clinical trial.

Based on that, they can estimate whether a treatment, or in this case a vaccine, will likely be effective.

“If the probability is looking good, there can be a trigger within that trial to say, let’s go ahead and take the risk of making a vaccine that may or may not work,” Smith declared, not being involved in the COVID-19 vaccine trials.

However, phase III clinical trials will still need to be completed before any COVID-19 vaccine can be made adequately available.

“Until the [phase III] trial is over, you won’t have total certainty whether or not the vaccine works, or if there are still some lingering safety matters.” Smith said.

More than 130 vaccine candidatesTrusted Source are being worked on worldwide, with 10 currently in clinical trials, from the World Health Organization report.

Fauci said a vaccine candidate made by biotech company Moderna in partnership with the NIAID could enter a phase III clinical trial by mid-summer, with testing sites in the United States and other countries.

This trial will involve about 30,000 people. The vaccine will be tested mainly in people ages 18 to 55, but Fauci disclosed that the trial will also include older adults and people with underlying health conditions.

Once people are given the test vaccine, scientists will have to wait for them to be exposed to the new corona virus before they can conclude whether the vaccine is effective.

How long this takes depends on the number of infections in the communities where those people live.

Fauci stated that if many participants live in areas “where you’ve had a big outburst or a surge of cases, you could get your answer pretty faster. Otherwise it could take months.

Question now, how long will the vaccine immunity  last

Fauci is “cautiously optimistic” that with multiple vaccine candidates being developed using various platforms, we’ll eventually have an effective COVID-19 vaccine.

However, Dr. Patrick Soon-Shiong, CEO of biotech companies ImmunityBio and NantKwest, thinks the big question is the duration of immunity produced by a vaccine.

When people develop antibodies to the common cold virus — that is caused by other corona viruses — the protection usually lasts less than a year. So, people may need to be vaccinated against COVID-19 every year, as with the flu vaccine.

Soon-Shiong adds that it’s not just the vaccine platform that matters for the durability of immunity, but also what part of the virus that’s being focused on

Currently, researchers have focused on developing vaccine candidates that can produce antibodies to one part of the new corona virus called the spike protein. ImmunityBio has adopted a different approach.

“There is no other vaccine developer that’s gone beyond just using spike, other than us,” Soon-Shiong stated.

The company is using a second-generation human adenovirus platform to target both the spike protein and the nucleocapsid protein, that is involved in replication of the virus.

The company’s vaccine candidate has been chosen for the White House COVID-19 vaccine development program, Operation Warp Speed.

It plans to begin phase I clinical trials of the candidate vaccine in June, with ability to produce 100 million doses by the end of the year.

Soon-Shiong says having just humoral immunity, or antibodies,could not be enough to assure long-term protection against COVID-19. But targeting the nucleocapsid protein at the same time can lead to longer lasting T cell immunity.

Some studies have discoverd that people who recovered from SARS in 2003 still possess memory T cells, which are reactive to the nucleocapsid protein of the SARS virus.

“That is the impetus for us to target cell-mediated immunity,” Soon-Shiong said.