As the ongoing coronavirus pandemic continues to grow, several companies are in a race to develop a coronavirus vaccine. Recently, Merck and Novartis have joined the global hunt for a COVID-19 vaccine.

Experts say that they are not sure whether a clinically safe and effective vaccine will be available this year.

Former FDA Commissioner Dr. Scott Gottlieb told CNBC this week, “I think we’ll have to have one more cycle of this virus in the fall, heading into the winter, before we get to a vaccine. I really think a vaccine is probably a 2021 event, in terms of having wide availability of a vaccine for the general population.”

Merck announced this week that it is testing two potential coronavirus vaccines. The first vaccine candidate is from Themis, a Vienna-based company, which Merck has acquired. The experimental vaccine contains a weakened version of the measles virus. Trials are expected in the next month.

For the second vaccine candidate, it is teaming up with a nonprofit organization, which is an existing Ebola vaccine. Trials are expected to start this year.

President of Merck Research Laboratories Dr. Roger Perlmutter said, “We are eager to combine our strengths both to develop an effective COVID-19 vaccine in the near term and to build a pandemic preparedness capability directed toward emerging agents that pose a future epidemic threat.”

Novartis also announced this week that it is planning to make a gene-based COVID-19 vaccine, which would be manufactured by AveXis, a subsidiary of Novartis.

The vaccine candidate is in development at the Massachusetts Eye and Ear hospital, the Massachusetts General Hospital, and the University of Pennsylvania.

AveXis President Dave Lennon said, “The COVID-19 pandemic is the most urgent public health crisis of our time and we recognize the significance of evaluating the potential role of a gene-based vaccine.”

The manufacturing of the Novartis vaccine candidate is expected to begin this month, with clinical trials expected to later this year. Many nations are counting on the coronavirus vaccine to get back to normal life. A survey has found that at least 7 in 10 people said it is important to have a vaccine as soon as possible so that nations can lift all restrictions.