SAN FRANCISCO (Reuters Breakingviews) - Companies jostling for Covid-19 vaccines is a labor opportunity. Amazon.com, Uber Technologies and Cargill are among the U.S. firms lobbying for their workers to get priority access. They have a solid case for why their staff who can’t work remotely are essential. But that should come with responsibilities as well as privileges. A vaccine shortage means government officials are making tough calls. A committee advising the U.S. Centers for Disease Control and Prevention decided on Dec. 20 that 30 million frontline essential workers, such as first responders, teachers and grocery store employees, should be part of the next wave of inoculations, along with people at least 75 years old. It will be up to states to decide whether to follow those guidelines. They can help such workers by tying vaccine access to better treatment of workers. It makes sense to prioritize companies that have been a lifeline to households during the pandemic, like Amazon. Almost 20,000 warehouse and Whole Foods Market workers have tested positive for Covid-19, or about 2.5% of the company’s staff that can’t work remotely. The infection rate for meat and poultry processing facilities was up to 8%, according to research by the National Academy of Sciences. Kansas has already said it will prioritize meat and poultry plant workers for vaccines given the industry’s importance to the state’s economy. But vaccination cannot be a free lunch for employers of essential workers. Companies such as Amazon have benefited from surging sales – and not just of essential goods – because of the virus. Jeff Bezos’ firm added $2 per hour in hazard pay at the beginning of the pandemic, but only for a limited time. The $2.5 billion it will have spent in additional compensation by the end of the year is less than 0.7% of Amazon’s expected revenue for 2020, according to Refinitiv. The government can hold companies accountable. A basic requirement might be that firms receiving priority access also dole out hazard pay or temporary raises of $5 an hour, a benefit some businesses offered but many rescinded. Longer-term, Congress and local authorities can also pass laws on mandatory sick leave and other safety nets, with a focus on businesses that have proven to be critical during the pandemic. Without such measures, part of the dividend from vaccines risks being unjustly diverted from essential workers to employers and their shareholders.