United Airlines became the first US airline that required all domestic employees to take enough numbers of Covid-19 vaccine.

United Airlines airlines said employees had to present Vaccine Covid-19 certification before 25/10 or 5 weeks after the US Pharmaceutical and Food Administration (FDA) licensed for vaccines of Pfizer, Moderna or Johnson & Johnson

The US is facing the outbreak of Covid-19 due to Delta transformation.

The fact that everyone will be safer when they are all vaccinated, United Airlines President Brett Hart and CEO Scott Kirby said in the Letter to its employees.

An aircraft of United Airlines takes off from Newark Liberty Airport in New Jersey, USA in December 2019.

US airlines are in the recovery phase after 2020 difficulties, when they have to reduce the frequency of flight, cut employees and borrowing money from the Government to pay salary caused by Covid-19 pandemic.

Kirby and Hart said some of the United Airlines employees may not agree with the requirements of compulsory vaccination, but confirming the guidelines have issued a workplace to be safer.

United Airlines issued a compulsory vaccination request in the context of increasing concerns about the impact of Delta transformation with the US aviation industry.

Union pilots United Airlines, representing more than 12,000 pilots to work for the company, said it is necessary to negotiate more about the requirements of compulsory vaccination with managing units.

United Airlines in May reached an agreement with the company's union about notaging vaccination, but will pay additional payments to anyone doing this.