Cases of breakthrough infections are being under-reported according to the Center for Disease Control, and Prevention’s (CDC’s) modified criteria, yet, in Massachusetts alone, there had been nearly 4,000 reports by June 12, per the NBC Boston

Vaccine breakthrough indicates those who still test positive of the Chinese Communist Party (CCP) Virus (or coronavirus) despite being fully vaccinated before. 

It is widely known that vaccination cannot guarantee full immunization to anyone, which means that a small but rare amount of people may still be subject to infection. In Massachusetts, the proportion was one in 1,000 fully injected recipients, or approximately 1% Department of Public Health data concluded.

On June 12, the state had recorded 3,791 cases of vaccinated individuals testing positive for the CCP Virus. Compared to the 3,641 breakthrough cases reported as of June 5, this was 150 more cases within just one week. Almost 4 million people are fully vaccinated in Massachusetts.

By April 30, as confirmed by CDC, 46 states in the United States recorded breakthrough infections, and the overall cases throughout the country were given as 10,262. At the time, 101 million Americans had been fully vaccinated against the lethal virus. Hence, the chances of breakthrough infection were 0.01%. 

However, the figure provided by the CDC could be lower than in reality. Not all inoculated patients will remain conscious of their vulnerability after the injection. Additionally, sometimes the infection is asymptomatic, which means patients would not think of getting tested again for the disease. 

The CDC stopped counting breakthrough infections last month. Federal health officials now only track vaccinated patients who end up in the hospital or those who die from the CCP Virus.

On June 22, the Bay State finally reached its 4.1 million goal of vaccinated residents—60% of its community. Infection rates in the area also saw a downward trend from 10 days before, with only 33 newly confirmed cases and one fatality. 

The concern left now is the chances of breakthrough infection. Although the available vaccines can offer protection against most virus variants, CDC said some of them “might cause illness in some people after they are fully vaccinated.”

Amid the total amount of breakthrough infections recorded on April 30, CDC noted that 64% of the situations came from other virus strains. 

Massachusetts was the first place in the U.S. to report the Indian strain of the CCP Virus, called the Delta variant. Since late 2019, experts have warned that it’s more contagious and lethal than its original version. 

This variant, unfortunately, was expected to be the very strain that can cause breakthrough infections. On June 15, it was categorized by the CDC as a “variant of concern.”

The Business Insider reported the likelihood of vaccine breakthrough caused by the Delta variant was still insignificant. 

“Public Health England analyses have found that two doses of Pfizer’s vaccine are still 96% effective at preventing hospitalizations—and 88% effective at preventing symptomatic COVID-19—from Delta cases. Two doses of AstraZeneca’s vaccine, meanwhile, are around 92% effective at preventing hospitalizations and 60% effective at preventing symptomatic COVID-19 from Delta,” the outlet noted.

Yet, the same protection will not be seen in recipients who only got one shot of the doses. Three weeks after the first shot, patients can only be guaranteed 33% immunization against the Indian variant.