California counties have dropped their Purple Tier status as the state saw a steady decline in positive cases and hospitals ceased to overflow with COVID-infected patients.

Governor Gavin Newsom announced his plan in early March to move California into the Green Tier by June 15, which would allow all businesses to fully re-open with minimal restrictions. The full details of restriction guidelines under a Green Tier have not yet been released, but facemasks are still expected to be worn.

A fourth wave, meanwhile, has already entered the country and hit states such as Michigan, Minnesota, Pennsylvania and Maine. The new, more contagious variant of the Coronavirus, B.1.1.7., seems to be the leading cause for these new cases.

There is a possibility that the unpredictable fourth wave could enter California, a state that has otherwise been seeing its lowest number of daily cases since the beginning of the pandemic.

Instructor David Dorado, who completed his graduate studies in Physiological Ecology and Biology at the University of California, Santa Cruz, provided further insight on the issue.

Dorado said the fourth wave if it were to hit the state of California, would most likely show up in geographical patches.

“If and when that fourth wave does hit, you will get areas that are socioeconomically impacted already,” Dorado said. He believed that these areas would be the pockets to start the fourth wave.

As of April 18, around 20% of Californians have received their first dose of the vaccination and a little over 30% have been fully vaccinated. California opened vaccination appointments to all residents 16 and older last Thursday.

According to data posted by the CDC, roughly a quarter of the American population has been fully vaccinated. As vaccines continue to roll out and all adults become eligible to receive the vaccine, the question that remains is how many would need to be fully vaccinated in order to reach herd immunity.

Herd immunity, Dorado said, is where there is a complete resistance to the virus.

Dorado admitted that herd immunity was not his area of expertise, but had discussed the matter with colleague virologists at the University of California, Riverside. Based upon communication with his fellow experts, David estimated that herd immunity would be achieved at around 80-85% of the population.

“And so when we’re talking eight out of ten people and California has somewhere around 20 or 30%, we’re a long ways off,” Dorado commented. “And that’s just California.”

There is the fact to consider that not all Americans are eligible to receive the vaccine. Only those 16 and older are able to get vaccinated, which sets a limit to what percentage of the population can be fully vaccinated. That is also to say that not everyone who is eligible to receive the vaccine may be willing to receive it.

Dorado said the possibility of the fourth wave hitting California is “very high” and that it could hit “very hard”. He said the vacations and activities of Californians would be the cause for the fourth wave to arrive in geographical patches. Those who come from a socioeconomically-deprived area will still want to go on their vacations, even when they have not been able to receive a vaccine.

This makes common areas such as beaches and amusement parks, Dorado added, a higher risk for spread.

In a briefing on Monday, April 19, Dr. Rochelle Walensky, director of the CDC, stated that the seven-day average of new cases in the United States is currently over 67,440 new cases per day. A month ago, the seven-day average had been just over 53,000 cases per day.

“While we are making extraordinary strides in the number of people vaccinated, we still have an extraordinary amount of disease out there,” Rochelle said during the briefing.

She noted that, while these vaccines work “extraordinarily well as prevention intervention”, the vaccination process still takes a month’s time before they are fully effective.

Adults who are eligible are highly encouraged to register for their vaccine appointment, which can be made by clicking on this link. More information on vaccines and vaccine distribution can be found at https://covid19.ca.gov/vaccines/.