Photo by Owen Beard on Unsplash.

The biopharma sector weathered the COVID-19 pandemic fairly well, with the Shares Nasdaq Biotechnology ETF IBB outperforming the S&P 500 Index. This defensive sector also benefited from opportunity in the form of SARS-CoV-2, the virus that causes COVID-19.

It, therefore, comes as a no surprise that two of the top five gainers among biotech stocks are vaccine developers. Here are the biotechs that advanced in excess of 1,000% thus far this year:

Novavax, Inc. (NVAX) (Gain: +2799%)

Much of Novavax's rally is attributable to its coronavirus vaccine program. The company identified its investigational vaccine, codenamed NVX-CoV2373, in early April. It is a stable, prefusion protein made using the company's proprietary nanoparticle technology, with Matrix-M adjuvant added to it.

Ahead of the initiation of the coronavirus vaccine program, the shares received a lift from positive developments concerning its influenza vaccine candidate NanoFlu. After proceeding seamlessly with its vaccine program, Novavax Is currently facing a setback as it is experiencing a delay in the start of the U.S. leg of the late-stage study of NVX-CoV2373.

With two companies having already received conditional approvals for their vaccine candidates, Novavax is under pressure to expeditiously bring its coronavirus vaccine program to fruition.

Vaxart Inc. (VXRT) (+1940%)

This South San Francisco, California-based company was among the earliest to embark on a vaccine program against SARS-CoV-2. The company announced in late January the initiation of the program based on its proprietary oral vaccine platform, VAAST. The company selected a lead candidate, an oral recombinant vaccine, in late May.

In a bid to expedite its vaccine program, Vaxart appointed Andrei Floroiu, a biopharma industry veteran with experience in vaccine manufacturing, as its CEO in mid-June. The company filed an investigational new drug application for commencing the Phase 1 study in early August, and the application was cleared by the FDA in mid-September. About a month later, the company commenced the Phase 1 study of the investigational vaccine, codenamed VXA-CoV2-1.