Pharmaceutical companies are scrambling to develop an effective COVID-19 vaccine and receive FDA approval. In the meantime, states are finalizing plans to distribute the vaccine -- and overcome potential challenges.

The Indiana State Department of Health released its interim draft on Tuesday and -- similar to other states -- will follow a phased approach. The department says the first recipients of a COVID-19 vaccine will be healthcare workers.

The Centers for Disease Control and Prevention recommends the flu vaccine for everyone 6 months of age and older, pregnant women, people age 65 and older, and people with certain chronic medical conditions.

If the vaccine is distributed to each state based on its share of the U.S. population, Indiana might receive only 300,000 doses initially for its 6.7 million residents.

State health officials are urging Hoosiers to get a flu shot this fall. The recommendation is an effort to keep flu numbers low during the coronavirus pandemic.

Pharmaceutical company AstraZeneca announced Wednesday morning that its COVID-19 vaccine trial is on hold after a volunteer in the UK had an unexplained illness.

The trial is for a vaccine in development by pharmaceutical company AstraZeneca and Oxford University. It's one of three vaccines in the U.S. in the final stage of study before Food and Drug Administration approval for widespread use.

Some parents are opting out of getting their children vaccinated, and last year that led to the worst measles outbreak the U.S. has seen in more than two decades.

Indianapolis Animal Care Services has seen over 50 parvo cases at animal intake in the last week.

IndyCar medical director Geoffrey Billows said Thursday a "very limited supply" of vaccines will be available at the medical building.