Why Kenya may not get the updated Covid-19 vaccine soon

Pfizer vaccine
Pfizer vaccine
Photo credit: AFP

Drug makers Moderna and Pfizer announced this week that they have updated their Covid-19 vaccine to tackle Omicron sub-variants responsible for new infections globally.

Vaccine experts in the country say the move is timely and vital but we might not get the new doses soon.

The two pharmaceutical companies use a new form of technology called messenger RNA (mRNA) that can easily be tweaked to suit new Covid-19 variants.

This comes as researchers from the Kenya Medical Research Institute (Kemri-Wellcome Trust) announced that the two Omicron sub-variants, BA.4 and BA.5 were responsible for the sixth wave in the country.

A sub-variant is a mini-version of the original variant that comes about when a virus changes its genetic composition.

With the ever changing mutations of the coronavirus, the US Food and Drug Administration had asked vaccine manufacturers to update their vaccines to suit the current version of the virus whose infections were rising at an alarming rate.

Scientists call the updated variant-specific jab a bivalent booster, which is the old vaccine with an added protection for the newer lineages of the virus.

Announcing the results of their study in June, Moderna said the bivalent booster would offer more durable protection against variants of concern.

"We are submitting our preliminary data and analysis to regulators with the hope that the Omicron-containing bivalent booster will be available in the late summer. Taken together, our bivalent booster candidates demonstrate the power of Moderna’s mRNA platform to develop vaccines that meet immediate, global public health threats,” they said.

However, the updated shots have not been approved for use by regulators at global level just yet.

Vaccine expert Moses Mwangi explained to the Nation yesterday that the virus has been undergoing mutation, highlighting the two variants; BA.4 and BA.5 as the most prevalent now.

“The virus seems to have drifted in a way that the current vaccines are not as effective as they were with the other strains. This only means that the vaccine has to be improved,” he said.

Dr Mwangi explains that for a vaccine to be manufactured, scientists identify a part of the virus that is likely to elicit an immune response. They call that part an antigen. After identifying the antigen, they weaken it to produce a vaccine that will trigger an immune response should someone come in contact with the virus.

“It is important to note that we do not introduce diseases to the body when manufacturing a vaccine since we remove the disease-causing part (pathogenicity),” he explains.

“For the Omicron sub-variant specific vaccines, the researchers had to use the Omicron antigen to make the vaccine,” he adds.

At the moment, only the United States has pre-purchased the vaccine, but Dr Mwangi says it should be available globally.

“The whole world needs it. But just like in the beginning, the circulation of the vaccine is likely to take a similar pattern. Good thing the current vaccines are still largely effective since they prevent severe disease and hospitalisations,” he said.

Speaking to the chairperson of the National Vaccine Taskforce, Dr Willis Akhwale, he told the Nation Kenyans will have to wait longer to get the bivalent vaccine.

“The process of making such decisions is lengthy since we need to have regulators’ input. We have to follow the process of policy change and in our country, the World Health Organisation has to approve first, we have our local researchers review it and then our local regulators,” said Dr Akhwale.

“We also look at a number of factors such as acceptability, storage of the vaccines and the economic aspect. It is too early to say when we will have it but we have to look at the safety as well,” he added.

Responding to whether we may need new vaccines every time a new variant comes up, Dr Mwangi explained: “The virus is just trying to survive, that is why it keeps changing. We may not need a new vaccine every time. So far, we have had about four variants but it is only Omicron that has been tested for a new vaccine. However, as is the case of the Influenza virus, scientists meet every year to discuss whether it is necessary to have an updated version of the vaccine or not. This is a cycle that is likely to happen for Covid-19.”