Moderna to begin phase 3 trials in July, Oxford to test Chadox1 on children

All you need to know about COVID-19 vaccines in the works

About 14 vaccine candidates in India have shown promise, said Dr Renu Swarup, Secretary of Department of Biotechnology, in an interview with Economic Times. She also said that India has about 30 potential COVID-19 vaccine candidates right now. Out of these, the recombinant BCG vaccine from the Serum Institute of India and Cadila’s Mycobacterium vaccine are in the third phase of trials already. Human trials for about three to four other candidates may begin in two to six months from now.

Additionally, Moderna Inc has reportedly started the mid-stage trials for its mRNA-based vaccine.

Here are all the recent developments regarding COVID-19 vaccines:

Moderna to begin phase-III trial next month

Last Friday, the American biotech company Moderna Inc reportedly began phase-II trial for mRNA-1273, their vaccine candidate for COVID-19. In this phase, the vaccine will be tested on about 600 volunteers.

The firm had released some initial results from their phase-I trial last month and had said that the vaccine showed promise. However, due to lack of insufficient data, a lot of questions were raised about the efficacy of the vaccine.

Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, has reportedly said the Moderna vaccine will enter phase-III trial in the first week of July. About 30,000 people will be enrolled in the trial, mostly from the age group of 18-55 years ,but also the elderly and people who are at risk of severe COVID-19. This phase will be the final stage of vaccine development. If the firm gets favourable results in these trials, the vaccine may be made available to the general population. Dr Fauci reportedly said that the results of the phase-III trial would be available by November or December this year, by which time, the company will already have produced about 100 million doses of the vaccine.

China may launch a vaccine by year-end

Chinese biopharmaceutical company Sinovac has reportedly said that they are 99 percent sure of the efficiency of their vaccine candidate CoroVac, which is an inactivated virus vaccine. The vaccine is in Stage 2 trials and the company is reportedly in talks to conduct their stage-III trial in the UK.

Meanwhile, China’s state-owned Assets Supervision and Administration Commission (SASAC) has revealed that the country may launch a coronavirus vaccine within this year. At least five vaccines are in the clinical trial phase in China.

Oxford University may try their vaccine on children

As schools are starting to reopen in the UK, Oxford University and AstraZeneca are reportedly planning to test the ChAdOx1 vaccine on children between the ages of 5 and 12.

The Oxford team will start recruiting volunteers for the vaccine soon. ChAdOx1 is an adenovirus vector-based vaccine that contains the sequence for the spike protein of SARS-CoV-2 virus. The spike protein is what the COVID-19 causing virus uses to latch on to and enter host cells. The vaccine is currently in Phase I clinical trials and has been given to more than 1,000 adults between the ages of 18 and 55, who are now being followed up to study the effects of the vaccine. It will soon enter phase II/III  trials, in which about 10,260 people of all ages from five to above 70 years will be included. Even though children are considered to not be at risk of severe disease, they will need to be vaccinated to stop the transmission chain of the virus.

Balance between fast-tracking and safety of vaccine crucial

In a study published in the peer-reviewed journal Science Advances, researchers have warned that going too fast may not be ideal when it comes to vaccine development.

As per the study, vaccines are fast-tracked on the basis of neutralising antibodies. However, there is always a risk of antibody dependant enhancement of the disease. In other words, the antibodies developed due to the vaccine may lead to more severe disease if the person is exposed to the pathogen. This kind of reaction has been seen in dengue, ebola and HIV vaccines.

Also, there is a need for a vaccine that stimulates not only antibody production but also the production of both CD4 and CD8 T-cells to provide complete protection against the pathogen.

The study concluded that a balance between fast-tracking the vaccine and the safety of the vaccine is needed.