Will new variants of Covid-19 affect vaccines?

Over the past few weeks, a new SARS-Cov-2 variant has been wreaking havoc across the world.

The new variant - delta - is currently the most dominant strain in the United States, which has been hardest hit by Covid-19.

Delta currently accounts for half of all new cases of Covid-19.

“The delta variant’s high rate of transmission and speed in infection is enabling it to pick off the more vulnerable people more efficiently than previous variants,” said Dr. Mark Ryan, the WHO’s executive director for health emergencies.

As the variant spreads, Covid-19 vaccine manufacturers Pfizer and BioNTech have announced that they are developing a booster shot to counter it.

New variants vs. vaccines

The delta variant is the third most lethal one to emerge since the onset of the Covid-19 pandemic in December 2019.

On December 14, 2020, the United Kingdom announced that it had recorded a new strain of the coronavirus.

The new strain - VUI-202012/01 - was reported to be 70 per cent more transmissible.

After this announcement, WHO reported the presence of the new strain in the Netherlands, Australia and Denmark.

Barely a week later, South Africa reported yet another new strain: 501.V2. It was said to have mutated more than the UK strain and quickly became the most dominant in new cases reported in South Africa.

On December 24, 2020, another strain was identified in Nigeria and named P681H.

Apart from these three strains, at least 31 countries have reported new variants of SARS-Cov-2, the virus that causes Covid-19.

These strains were countered with existing vaccines and appeared to have been subdued.

However, towards the first quarter of 2021, a new highly transmissible variant was identified and reported in India.

The variant dubbed India Variant was first recorded in Kenya during the first week of May 2021.

It was first reported in Kisumu from travellers from India. Two months later, the world is now grappling with the highly lethal delta strain.

All of these strains come amidst a concerted global effort to get people vaccinated.

However, there are concerns on the progress of vaccine development as well as the socio-economic and health impact that Covid-19 mutations will have on the fight against the pandemic.

Take the VUI-202012/01 strain from the UK for example. From December 21 2020, the United Kingdom imposed restrictions in London and Southern England where the new variant was mostly spreading.

Multiple European countries including France, Italy, and Germany imposed a ban on all flights from the UK.

By December 22, over 53 countries had banned flights to the UK. However, Kenya announced that it would not ban any flights from there.

According to Health Cabinet Secretary Mutahi Kagwe, Kenya favoured tougher traveling measures for passengers arriving from the UK than a total ban on flights.

“We have stricter travel measures with the United Kingdom than the US and the Europeans have. We are carefully observing passengers traveling from the UK,” said Kagwe.

More strains to come

According to Dr. Moses Masika, a virologist at the University of Nairobi, the emerging strains might just be the tip of the iceberg. “New strains of the coronavirus will keep on developing,” he says.

Majority of countries that have been reporting new strains are those that have been conducting virus genome sequencing to determine virus characterisation.

“Kenya and the majority of African countries have not been doing genome sequencing. This means that the new strains of coronavirus might already be in the country, but have not been detected yet," says Dr. Masika.

He however points out that anyone who contracts a new strain will still test positive for Covid-19 when tested using current diagnostic tests.

Mutations and transmissibility

The most troubling characteristic of the new strains is multiple mutations. 

Dr. William Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health, is one of the researchers who have been leading Harvard University’s Covid-19 research.

According to him, unlike existing coronavirus variants, the new strains are characterised by many mutations.

“The new strains from the UK and South Africa were independent of each other, but they shared some related characteristics. One of these was the mutation S:N501Y which glued affinity to the receptor the virus uses to enter cells,” he said in a Harvard research report on SARS-Cov-2.

Due to their high rate of transmission, Dr. Masika says the presence of new strains should be of concern to the national efforts against Covid-19. However, Kenya should not panic just yet.

“There is no current evidence that the new strains cause more severe Covid-19. They are not markedly different from other strains, despite their ability to spread faster,” he says.

In addition, Dr. Masika says the new variants have not all been proven to be resistant to the already developed Covid-19 vaccines.

“These being new strains, there is no established evidence that they are absolutely resistant to the current vaccines,” he says.

Health protocols

One way to ensure the newly developed vaccines don’t lose out to new variants is by constantly monitoring their efficacy.

“We need to keep on collecting information to confirm that the vaccines are still working in the face of new variants,” he says.

In addition, Dr. Masika says Kenya should continue to observe the current health measures and protocols against Covid-19.

“The current health measures are adequate in curbing the spread of the new variants as well as diagnosing people who may have new strains,” he says.

In Kenya, over 1.05 million people have been tested for Covid-19. Out of these, 97,000 have tested positive for the virus. Over 1,600 have died while 78,800 have recovered. 

Previous virus strains

Although SARS-CoV-2 has been a fairly new virus, the world can take comfort in knowing that previous related virus mutations did not affect vaccine development.

In January 2009, a new H1N1 influenza virus was detected in humans.

This virus, which caused swine flu, quickly mutated and led to an influenza pandemic that lasted from January 2009 to August 2010.

Swine flu was reported to be the result of new strains of H1N1 and H3N2 strains of the influenza virus.

However, the virus mutations did not affect vaccine development. By December 2009, influenza vaccines were returning 95 per cent effectiveness and cutting hospital admissions by up to 64 per cent.

These included the live attenuated influenza vaccine which was a nasal spray flu vaccine, and the TIV flu shot.