Dr Christine Carrington

KEVON [email protected] scientists project 12-18 months before they can deliver a COVID-19 vaccine to the world, there remains uncertainty over its effectiveness and when it will reach T&T.At yesterday’s Ministry of Health COVID-19 update, Dr Christine Carrington, Professor of Molecular Genetics and Virology at the University of the West Indies, said the availability of a vaccine in T&T would depend on the production rates and quantities.

“An effective vaccine against SARS-CoV-2 may likely be the only long term solution to controlling the COVID-19 pandemic. To date, there are over 125 vaccines in development and the level of these have reached the stage of clinical trials, meaning that they are being tested in humans,” Carrington said.”Vaccine development is a long and complex process, involving preclinical laboratory studies, animal studies, then several levels of what we call phases of clinical trials, involving vaccination and the subsequent challenge of people with the virus. If a vaccine is proven to be safe and effective after all of this, then there are difficulties transitioning to manufacturers. Manufacturing has to be done on a large scale under the very strict condition and finally you move to distribution.”

According to National Geographic, the mumps vaccine is considered the fastest ever approved, taking four years from collecting viral samples to licensing a drug in 1967.Last month, African Union chairman Cyril Ramaphosa called for any COVID-19 vaccine that is developed to be made patent-free, produced at scale and made available at no cost globally.At a World Health Organisation’s (WHO) World Health Assembly held last month, a unanimous resolution was passed by the 194 WHO member states, calling on the Director-General Tedros Ghebreyesus to rapidly identify and provide options for scaling up the development, manufacture and distribution capacities needed for providing access to COVID-19 diagnostics, therapeutics, medicines and vaccines.Carrington said vaccine development averages about 10-15 years but for COVID-19 there are collaborations between private and public entities to speed up the outcome.”Even at this accelerated rate, many experts believe that it will be about 18 months before a vaccine is ready for rollout,” she said.Carrington said there was optimism that one of the vaccines under clinical trials will be ready before the year ends.

The Univerisity of Oxford’s AZD1222 SARS-CoV-2 vaccine is touted as the most advanced, she said. Formerly called ChAdOx1, it is the weakened version of an adenovirus (common cold). Carrington said this causes infections in chimpanzees but was modified so that it could not multiply in human cells.

“Initial human trials show that it is safe and well-tolerated and triggers a strong immune response that is able to recognise SARS-CoV-2. Animal studies show that although vaccinated animals can still be infected by SARS-CoV-2, the level of virus is lower than in unvaccinated animals. The vaccinated animals did not develop pneumonia, so there is some level of protection,” Carrington explained.A phase three clinical trial involving 10,000 UK volunteers will now determine whether people who received AZD1222 vaccines are less likely to contract COVID-19 or develop symptoms against those who were given non-COVID-19 vaccines, she said. The results are expected in August.However, Carrington said with infections slowing down in the UK, there is a concern about whether there are enough infected people for researchers to determine the difference between the two groups. Even before those results return, the Coalition for Epidemic Preparedness and Innovations and AstraZeneca are preparing to produce 2 billion doses of the vaccine. This includes 400 million from the US and UK and 1 billion doses for low and middle-income countries.”If the vaccine is proven to be safe and effective, the first doses are anticipated to be available later this year and the first 300 million ready by July next year.” China’s CanSino Biologics and the US’s Moderna are also developing similar vaccines that have been well tolerated so far.While a COVID-19 vaccine will go a long way to helping countries to return to normalcy, Health Minister Terrence Deyalsingh noted that anti-vaxxers exist in T&T. Deyalsingh said there were even anti-vaxxers in the Parliament.

In 2019, WHO listed vaccine hesitancy as one of 10 threats to global health.

But Carrington was not worried by those people, saying that once there are enough people vaccinated in a population, the chance of an outbreak is low as there would be “herd immunity.” However, she acknowledged that for some vaccines, those who are immunocompromised, very young or old, may not be able to be vaccinated. Some people also develop allergic reactions to vaccines.

As for preparedness, Deyalsingh said it was too early to determine how the vaccination would roll out as the ministry would have to know the various protocols for storing and dispensing. Once a vaccine is developed, he said the ministry would work with the Pan American Health Organisation to vaccinate the populations.