Moderna scientists and executives have warned that new COVID-19 variants are coming out. The company's chief scientific officer, Melissa Moore, said that the virus is rapidly mutating as the virus spreads.

Moore noted that some of the new COVID-19 variants strains could be more contagious, according to a Deadline report.

She said they know that the current Moderna vaccine is less effective to some of the new strains. However, she said that the company is constantly testing its vaccine against emerging variants.

Guillaume Stewat-Jones, a Moderna scientist, said the shortest time from detection of a variant "to preclinical immunogenicity readout against a panel of pseudoviruses" is about two to three months.

Stewat-Jones noted that new variants are coming and constantly emerging in real time, WION News reported.

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COVID-19 Variants

The three main COVID-19 variants that cause concern in the United States were first identified in the United Kingdom, South Africa, and Brazil.

Scientists are not surprised by the new variants. They noted that existing vaccines should still work against them, although with less effectivity than the original viral strain, CNBC reported.

Andy Slavitt, White House COVID-19 senior advisor, earlier said that the next wave of cases might have to be with the B.1.1.7, which was first identified in the U.K.

Dr. Dennis Burton, the Scripps Research Institute chair of immunology and microbiology, said research shows that worrisome virus variants could come from immunocompromised people. 

Burton noted that those who are immunocompromised take longer to clear the virus in their bodies. He said that it gives the coronavirus more time to figure a person's immune system and mutate. 

He added that an immunocompromised person carries the virus for weeks, giving the virus more chance to mutate.

The Centers for Disease Control and Prevention (CDC) Director Dr. Rochelle Walensky said the B.1.1.7 variant is thought to be around 50 percent more transmissible, and early data suggests that it could be up to 50 percent more deadly.

COVID-19 Vaccines

A study found that two doses of the Pfizer/BioNTech and the AstraZeneca vaccines provide protection against the COVID-19 variants that were first identified in India and U.K., according to a WebMD report. The study had highlighted the need for two doses as one dose of the vaccines provided much less protection.

The Public Health England study said that the Pfizer vaccine was 88 percent effective against the variant in India two weeks after the dose. On the other hand, the Pfizer vaccine was 93 percent effective against the variant found in the U.K., two weeks after the second dose.

Meanwhile, the Johnson & Johnson vaccine's efficacy for mild to moderate COVID-19 14 days after vaccination was 66.3 percent overall. 

In the United States, it was found to be 74.4 percent effective. In Brazil and South Africa, the J&J vaccine offers 66.2 percent and 52 percent protection, respectively, Healthline reported.

However, the J&J and Moderna vaccines' protection longevity is currently unknown, while Pfizer offers protection for six months.

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WATCH: EMA: Pfizer, Moderna Vaccines Effective Against COVID-19 Variants - From WION