The deals also eliminate the two-tier system at a handful of Big 3 plants.

Scientists still think reinfections are fairly rare and usually less serious than initial ones.Gottlieb says vaccines should offer reasonable protection against coronavirus variants 06:08 Doctors in South Africa began to worry when they saw a surge of cases late last year in areas where blood tests suggested many people had already had the virus.

Ester Sabino of the University of Sao Paulo.is that past infection with early variants of the virus in South Africa does not protect against the new one.Stuart Sealfon of the Icahn School of Medicine at Mount Sinai in New York.

The study involved several thousand Marine recruits who tested negative for the virus three times during a two-week supervised military quarantine before starting basic training.That work was done before the new variants began to spread.

California scientists also are investigating whether a recently identified variant may be causing reinfections or a surge of cases there.

08:43 Reinfections pose a public health concern.Every year of work there erases one year of the debt covered by their award.

The losers are more sensitive to reductions in the rates for the procedures they do.No one would claim that doctors are poorly paid.

The new code is a tiny piece of overall payment reform.It would let physicians bill for complex patient evaluation and management services.