An eventual coronavirus vaccine will likely require two separate injections, possibly a month apart, due to the newness of the virus, according to a Harvard professor.

A double vaccine might be the only option to build immunity against the respiratory infection as COVID-19’s properties are so new to the world that people are not able to produce antibodies to effectively combat it, USA Today reported Thursday.

“As far as I am aware, with one set of exceptions, all the front-line vaccine developers are contemplating two shots,” Harvard health professor Barry Bloom told USA Today. “The one exception is Merck, which last week pushed forward on two vaccines, each of which they hoped would be one-shot vaccines.”

You Might Like

The idea behind a two-shot vaccine is that the first injection allows the body to recognize the virus, while the second, which comes around a month later, brings about a heightened immune response to the infection. Medical professionals have yet to determine the exact dosage, but seem to generally concur on how it should be administered, USA Today reported.

“The immune system looks at it and it processes and remembers it, developing antibodies and immune cells,” which takes about 14 days, L.J. Tan, chief strategy officer with the Immunization Action Coalition, told USA Today. “If an infection comes at that point you’ll fight it off and you won’t get sick – you’ll be immune.”

Double vaccines are common for both children and adults to inoculate against measles, pneumonia, meningitis, tetanus and other serious diseases.

Worldwide coronavirus cases have surpassed 6.5 million with around 1.85 million of these in the United States. Approximately 386,000 have died from disease with 107,000 American deaths, according to Thursday update from the Johns Hopkin’s coronavirus map.

A company called Moderna is in the midst of creating a COVID-19 vaccine, and entered what’s known as “Phase 2” of testing in early March after receiving government permission, Time reported.